Talking to a scientist about Hydrodynamics relating too the "red tip", "winged keel" and "star fin"...

Well for those interested…

Today i had a very interesting and informative conversation with a scientist and teacher about these hydrofoil type fins.

We came to the conclusion that the fins needed to reach high speeds to actaully work as intended.

The winged keel on sailing boats like Australia 2 is useful because you can turn the boat on a high angle while keeping the boat in the water and stable.

On surfboards the winged keel is not of any advantage on small wave boards as you need to go very fast and the winged keel “lifts” and “stabilizes” the board, Just drag if you ask me.

We then talked about the FCS Redtip fin. As he put it the fin is a gimmic! it has little or no affect in small waves but creates more drag. he said “you’d only notice a tiny improvement in the fin in the correct surf”. That said i am very sensitive to surfboard alterations and in good g’land style waves i feel the the fin would be a definate advantage. But for the kind of aussie surf we get so often its just not worth the trouble.

The one thing we did fin was a definate advantage was the hydrofoils in the boards Laird Hamilton and crew use in giant waves. For one it lifts the board out of the water and secondly it keeps you stable in very fast, huge and choppy waves where a normal tow board would slide and become difficult.

We got talking into more technicalities then that but this is an undistandible overview which i believe is correct.

that said i’ve only ever rode a winged keel once and would love to be proved wrong…

Cheyne Horan illustrating what was said about the winged keel in boat designs.

i toatally agree with you mate. with my fcs redtip i didnt notice a single advantage nor dissadvantage. It is just something that sounds cool but honestly has no effect.

Funny how we bring this up just after my fcs redtip dissapiered out in the surf that day ay josh. The surf gods predicted that they were no good and and got rid of it for me.

oh well such is life. mind you they coast a fourtune

The proof is in the water, not the scientist’s head.

The single fin starfin has exactly the opposite speed relation postulated by your scientist…it provides a substantial advantage in smaller waves, and its advantage fades with more speed.

I think you need to start by considering whether these are wing-tips to prevent induced drag, or hydrofoils intended to provide lift. Or both.

" Today i had a very interesting and informative conversation with a scientist and teacher about these hydrofoil type fins."

hi josh !

if the guy surfed these fins for a year every day , and his observations were based on that EXPERIENCE , it may mean a bit more to me , personally .

A lot of the theorists are just that ...

"practicists " are more what I learn from , listen to more , and seek out .

but , in the end , when it is all said and done , I still MUCH prefer trying stuff out for myself ! [you know what they say about “opinions” , eh ? heehee]

…I quite like my winged keel in my 6’4 and 7’ers , I probably need to give it a few goes [?next winter?] in my 5’7 stubbie on a head high day , to comment more about its performance on a short board …

[…can you , and / or others here , remind me just before next winter , to use the “winged keel” in my ‘stubbie’ please , Josh ? cheers mate !]

  ben

Hey Josh, my name is John Harris and I invented the Red tip and I take offence of you calling my fin a gimmick. You said you were talking to a teacher, scientist. Does that mean you are a student, and how old are you? I am 51 years of age and have been shaping for 36 years for my living, I first shaped the 3d out of a solid block of foam in 83, before Cheynes fin . This is difficult to say without blowing trumpets, but fact is I have shaped and surfed first grade for over 30 years and if that fin didn’t blow my mind from the first surf , why do you think I would have stuck with it all these years? money, think not, have got bugger all out of it. Do you think Kong[ who has got the same as me] would have had it permanently in his board from his first surf on it about 3 years ago. The fin will go equally as good in small waves as in bigger stuff and answer this , have you surfed it and can you surf at a level to know the difference. Not all things are for everybody, but untill you drive a hard slash under the lip on a solid wave or drive a round house cutback and realise your’e not loosing any speed and you have totall control through the white water or have least ridden the fin, keep your small minded opinions to discussions in your class room. And you can tell your teacher to teach what he really knows and that isn’t my fin. John Harris

Well Mr. Harris,

What you call YOUR winged keel fin, was prototyped by me, with help in the molding by Buzzy Smole, while we were both shaping at Hansen Surfboards, in 1966. I have also seen variations of winged fins as early as 1957/58 by Alan Nelson of La Jolla, and I believe Alan was influenced by Bob Simmons. Josh had it right in some respects. It’s a ‘‘gimmick’’ in the respect that the most you can hope for is that the use of it would not slow you down, or impair the performance of an otherwise good surfboard. The best that can be said for it is that it is useful for the narrow application of noseriding. IF it was really the end all of fins, it would have been embraced by the industry in the 23 years since you ‘‘invented’’ it. Don’t you think? By way of qualification to comment, I’ve been surfing and shaping boards as long as you’ve been alive. As to why you stuck with it all these years, only you can truely answer that. However the example of the monkey with his hand on the fruit in the gourd, and not being able to let go, comes to mind. Same can be said for Mr. Tinkler and his famous tail. Just can’t let go.

In world full of double talk and political correctness…Bill ,your straight talk is refreshing!!

Roger

aw shux

and here I fhought

all the quwestions were answered

and I could shave my temples

and begin worshiping the

new god-fin/.

demmit mr kill

now I Have to go back to my aimless wandering

in the desert

…ambrose…

Hello Mr Thrailkill, what’s nose riding got to do with a 4" thruster back fin setup. Sorry firstly I should say I only invented that fin and when I shaped it out of a block of foam, I honestly had not seen one fin like it, or the Australian 2 winged keel , that gave me the idea. I just grabbed a block of foam and carved it out. It went on a 6’1" thruster and the board went so good, my brothers and friends wanted one [fin]. My brother Robert was making a living out of conversions [putting a wing on the back fin]. Multi fin produced moulded ones and they sold 10,000 fins in the first 3 months. So it was embraced , it’s no suprise to me that the 3D hasn’t done the same numbers, because of the price. I have no control on that. Cheyne’s fin has been spoken of having good noseriding advantages, it’s a single fin. You are an elder Mr Thrailkill and for that I have great respect. If you have been shaping since 58’ and you were say 15 when you started that would make you around 63. With all due respect , I am not talking about mals or noseriding and I will take any criticism standing up, if the person knows what they are talking about, J.H.

John, out of curiosity, what do you think that you are achieving by having that tip on your rear fin? -Carl

There’s this thing in anthropology called parallel - sometimes even convergent - evolution.

I personally think its rediculous to claim stuff like this. Yeah, this date, that date. Whatever. Lots of people have good ideas.

In the end, its not ideas, but marketing that wins. Unfortunate as that may be.

If you made something neat, enjoy it. Pimp it all you want. Or shut up about it. I don’t care.

John,

For the record, I started surfing at age 14, and shaped my first balsa board at age 17. I’m 65 now, and will be 66 in February. YIKES! Where the hell did the time go?? You sound like a stand up fellow. I’m sure we would have much in common in our experiences. I just thought you landed on Josh a little harder than necessary. That aside, and behind us, WELCOME ABOARD SWAYLOCKS. I’m sure you have much to comtribute to the forum.

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Well Mr. Harris,

It’s a ‘‘gimmick’’ in the respect that the most you can hope for is that the use of it would not slow you down, or impair the performance of an otherwise good surfboard.

Quote:

Absolute nonsense ! Fins with horizontal area ( ‘hydrofoil fins’) work well for those who understand what they do. . . . it is a hydrodynamic fact that underwater foils can provide lift at a better lift/drag ratio than simple planing surfaces. Your criticism of horizontal foils is always based on two ideas: (1) That you are an expert and so if you say they don’t work then it must be true (2) That they have not been widely accepted by the mainstream surf industry or pro surfers therefore they don’t work Both of these arguments are pure BS.

IF it was really the end all of fins, it would have been embraced by the industry in the 23 years since you ‘‘invented’’ it.

Quote:

Not necessarily. . . . the surf ‘industry’ only promotes a couple of distinct approaches to waveriding to the exclusion of a lot that is of worth. . . in other words the surf industry isn’t the be all and end all of surfing. . … as many people on this forum know. Besides, Mr Harris didn’t say that it was the ‘end of all fins’ !

As to why you stuck with it all these years, only you can truely answer that. However the example of the monkey with his hand on the fruit in the gourd, and not being able to let go, comes to mind. Same can be said for Mr. Tinkler and his famous tail. Just can’t let go.

What an insulting thing to say to Mr Harris !. . . . the fact that your status allows you to insult the work of others with impunity on this forum is really a black spot on the whole place, has it occured to you that you might cause a lot of suffering to those whose work you scoff at?

If not, it should.

.

i agree with benny

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There’s this thing in anthropology called parallel - sometimes even convergent - evolution.

yeah aussie shapers were trying similar stuff as the US through surfings evolution

for some one to claim, concaves and such tail shape ,blah de blah blah

wing blah de blah

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Hey Josh, my name is John Harris and I invented the Red tip and I take offence of you calling my fin a gimmick. You said you were talking to a teacher, scientist. Does that mean you are a student, and how old are you? I am 51 years of age and have been shaping for 36 years for my living, I first shaped the 3d out of a solid block of foam in 83, before Cheynes fin . This is difficult to say without blowing trumpets, but fact is I have shaped and surfed first grade for over 30 years and if that fin didn’t blow my mind from the first surf , why do you think I would have stuck with it all these years? money, think not, have got bugger all out of it. Do you think Kong[ who has got the same as me] would have had it permanently in his board from his first surf on it about 3 years ago. The fin will go equally as good in small waves as in bigger stuff and answer this , have you surfed it and can you surf at a level to know the difference. Not all things are for everybody, but untill you drive a hard slash under the lip on a solid wave or drive a round house cutback and realise your’e not loosing any speed and you have totall control through the white water or have least ridden the fin, keep your small minded opinions to discussions in your class room. And you can tell your teacher to teach what he really knows and that isn’t my fin. John Harris

Nice to hear your words of wisdom Mr Harris

.

Roy,

Go back to the shop and work on your high drag, slow, water constricting, tunnel fins. Or, you could just let go of the fruit in the gourd. While I consider myself to be knowledgable on these sort of matters, I defer to your expertise on/in BS. Cheers!

Mr Thrailkill.

Here are a few facts:

(1) The tunnel fin is the lowest drag fin configuration possible

(2) The tunnels do not constrict water flow

(3) Horizontal area fins are able to reduce drag and increase speed, as Mr Harris has noticed

Please don’t try to ‘tell’ me what to do, and please stop insulting people on this forum. . . it really sucks that you can get away with continually scoffing at the work of others. . . . it’s really just trolling of the worst form.

.

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your high drag, slow, water constricting, tunnel fins.

That is the stupidest statement I have ever heard on this forum. . . . .

and there’s no excuse for it, as you have already been told the hydrodynamic facts regarding tunnels many times.

Please don’t be a stoke killer

.

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There’s this thing in anthropology called parallel - sometimes even convergent - evolution.

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   Yes, and it IS fin evolution we are talking about regardless of what Josh's teacher and Mr Thrailkill say     
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In the end, its not ideas, but marketing that wins. Unfortunate as that may be.

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   Only true if making money is the design goal. . . if one is just out there to explore fun surfing possibilities, then marketing is irrelevant        </blockquote></div>

If you made something neat, enjoy it. Pimp it all you want. Or shut up about it. I don’t care.

Word !!

I’m so glad you are here Benny

:slight_smile:

Facts? Facts indeed. Only in your mind, Roy. Scoff, scoff, scoff. Hmmm, I must be catching a cold.